You might expect to hear the word at the Royal Court or on the fringe, but not in the faded Edwardian gentility of the West End. When Eve Ensler first said the word "cunt", a little gasp rippled through the audience. Within 90 seconds she had most of the audience chanting the word. We were, she declared confidently, "reclaiming cunt". If only it was as simple as that.

Ensler's show, inspired by hundreds of interviews with women from Bosnia to New York, has become a world-wide phenomenon. It has not changed much; the jokes are much the same as they were when I caught a British try-out in a Bloomsbury arts centre three years ago. But now movie and TV stars such Calista Flockhart queue up to share a stage with Ensler and reclaim "cunt". This is a piece of theatre that could easily be franchised. Ensler could become a vagina entrepreneur. A cross between a 1970s consciousness-raising meeting and a stand-up set, the show combines the intimate jokiness of women gossiping with facts and her own monologues. These range from a 72-year-old New Yorker talking about "down there" in terms of a cellar with a leaky pipe to a Bosnian doctor's appalling experience of rape.

Some of these stories are amusing, some are moving, and some, like the one supposedly based on the words of a six-year-old girl, delivered complete with twinkly fairylights and snowflakes, are toe-curling. At this point in the evening, my vagina was urging me towards the door marked "exit".

What is curious about the evening is that for all its claims to empowerment, it is packaged to resemble one of those coy adverts for sanitary protection that never mention anything messy. Ensler may say the words out loud, but they are accompanied by soft-focus lighting, clouds drifting across a sky, pictures of flowers or of the Earth taken from space.

In the end this show is about as radical as deciding not to shave your legs this summer. Ensler seems to believe that she is striking a blow for feminism to suggest that women are their vaginas. Actually, the struggles of the past 40 years have been an attempt to show that we are so much more than just cunts.